Lithium batteries are currently used to power many biotechnologies. However, these batteries are non-renewable, heavy, lack longevity, and are toxic, creating critical problems as a power source in the human body. We wanted to find a way to harness a more renewable and natural energy source. To do so we planned to manipulate natural metabolism of excess fat in the body so that a localized heat source could be created and cause a changing magnetic field to induce a current.

To do this, a pill containing the hormones glucagon and noradrenaline, a magnetic nanodevice, and a high threshold leptin sensor is ingested by a human. This pill, coated in a thin layer of a fat-like hydrophobic molecule, will be directed towards the excess fat in the body. Since white fat cells excrete a very high concentration of the hormone leptin, the pill will find these cells using the built-in leptin sensor. Once at the white fat cells, the pill will release the glucagon which activates the first step in the process of fat metabolism. In order to break down fat in the body, fat must first be broken down into glycerol and fatty acids. Lipolysis is the complex process that breaks down the bonds between glycerol and fatty acids in fat cells. Glucagon is a hormone that activates the lipolytic response in fat cells. We specifically chose to include this hormone in our pill because we wanted to manipulate the natural process of fat metabolism. The pill then releases noradrenaline to stimulate the oxidation of fatty acids. Noradrenaline is a hormone that activates the enzyme cascade that stimulates the oxidation of fatty acids. These processes are exothermic, releasing heat. The heat source in this localized area causes a temporary change in the molecular structure of the magnet, causing a change in the strength of the magnetic field produced by the iron nanodevice. This increase and decrease in magnetic field can then induce a current through a loop with a biotechnological device, effectively powering it.

In the future we hope that our design could sustainably power a pacemaker without having to implant any sort of power source; instead a patient would just have to periodically take a pill that then naturally produced the heat and induced a current. Our project could also potentially be scaled up to allow for external devices, like a phone, to be wirelessly powered by breaking down fat within the body!

Also, our design could potentially revolutionize weight loss. White fat cells (adipocytes) can only be shrunk but not lost, and harnessing energy from the breakdown of fatty acids will help shrink these fat cells. With our idea

electricity would be able to be wirelessly induced in biotechnology rather than having a wire connecting the two. Using the changing magnetic field as a way to power biotechnology will introduce an alternative to lithium batteries. Also, harnessing energy in this way requires no invasive surgeries or permanent implanted device (other than the biotechnology this process powers).

There are still limitations to our current design. No research has been done to numerically show how much the magnetic field is altered when introduced to the localized heat. Also, the fat-like coating around the magnet would likely limit the amount of heat transfer to the magnet since the substance is not a conductor of heat. This would in turn limit the change in the magnetic field. Faraday’s Law, which describes the process of generating a voltage in a loop of wire from a changing magnetic field is not a very efficient process. A significant amount of energy may be lost due to several factors: the strength of the magnet, how much the magnetic field changes when introduced to heat, the speed at which the magnetic field changes, and the distance between the magnet and the loop within the biotechnology. Also, our design requires a patient to periodically take pills in order to sustain the power to their biotechnology. This could cause problems if a patient was to forget to take the pill, so an alternative source of power might be needed as a precaution.

To improve our design in the future we want to improve the type of magnet we use and the way that the field is altered. More specifically, better materials could be used to enhance efficiency of heat transfer to the magnet. Moreover, there are feasible ways to connect magnets so that changing heat can expand them and cause a rotation between them, effectively turning off the magnet by changing the flow of the magnetic field lines. This would cause a more drastic change in the magnetic field, more efficiently generating electricity. We also want to improve the methods of how the pill finds the excess fat in the body and want to consider an alternative to having a patient continuously take pills.

Dependency on batteries and external energy sources has really limited the compatibility of several possible healthcare devices and make it harder for patients to constantly have peace of mind.

Toxic material

Lacks longevity

Heavy

Non-flexible

Nonrenewable

Introduce topic of harnessing energy from human body

How much power the human body holds/is capable of generating

Why this source of energy is better than lithium batteries

Different areas of harnessing power

Movement (piezoelectricity)

Heat (thermodynamics)

Glucose Fuel Cells (Enzymatic Fuel Cells)

Current Technology

Glucose-based fuel cells

The use of glucose enzymatic fuel cells will allow users to use various nanotechnological devices that could allow patients to monitor various portions of the body, allow easier application of medications, reducing the need for constant monitoring and aid from nurses and loved ones.

Explain how they work

Explain the challenges

Interfacing with human body

Specifically Enzymatic fuel cells

Our decision to focus on EFCs

Why we chose EFCs

Because they are the most natural form of harnessing power from the body over the other forms

Take electrons from the glucose in the plasma of our blood

What is the largest benefit of using them over other technology

What are the challenges still

Direct Electron Transfer (DET)

Mediated electron transfer (MET) – finding the right molecule

It has been shown that the correct composition of the molecule mediating the transfer of electrons can idealize the amount of power generated

This molecule must have the right potential to allow electrons to most easily be transferred

Our Technology/ Idea

What it is/how it works…

These are enzymatic fuel cells that oxidize glucose through redox reactions in order to transfer the electrons from the glucose in the plasma in our blood and create an electric potential/electricity.

Why it is better…

Harnesses more energy, faster – more efficient

Is more natural to the human body, working with natural reactions rather than external “hardware” which the body does not simply accept

More power

Has potential to transfer electrons faster and at greater mass than the alternatives

Possible applications for the future

This application could be used in an assortment of nanotechnologies that could be used for patients that are categorized in an array of age ranges.

Patients that are dependent on their blood pressure monitors could have a device implanted that can give constant updates and could alert them and their family members when it reads dangerous levels.

A younger child that suffers from a heart defect or specific infections could use a implanted device to monitor their health without the discomfort or dependency of remembering to charge any device or sit by an outlet for an extended period of time.

Our group wants to find and improve the most beneficial option for harnessing power from the human body in order to power implantable devices. We’ve decided that we want to focus on using glucose fuel cells and specifically glucose powered enzymatic fuel cells to harness the power. The existing research on these fuel cells shows challenges with the interface between the fuel cells and the human body. Since the fuel cells convert chemical energy into electrical energy by oxidizing glucose into gluconolactone and reduces oxygen into water, and glucose is abundant in the blood, these fuel cells must directly interact with bodily fluids. Due to interfacing challenges, the fuel cells are not as efficient as they could be. Our group plans to redesign an enzymatic fuel cell so that the cells can have a more efficient interaction with the body. Mediated electron transfer (MET) has been shown to enhance this process by using a molecule with a correct potential for the redox reaction to transfer the electrons from the biomass to the enzymes. If the composition of these small molecules is optimized for the body, it can actually increase the rate at which the electrons are transferred to the enzymes, and therefore generate a larger current (more power). This has been shown to have the potential to transfer electrons faster and at greater mass than the alternative, which is Direct Electron Transfer (DET), where the electrons are directly transferred to the enzymes. This idea would improve what is currently out there because it would make fuel cells that are more effective so that the energy they generate can have enough power to charge implantable devices in the body.

Biofuel cell technology is another option to power nanotechnology inside the human body. The article below discusses renewable biofuel cells that are glucose-based. Instead of using batteries, an implantable device can extract its source of energy from biofuel cells within the body. The article discusses how biofuel cells can convert the chemical energy of biofuels like glucose into electrical energy through oxidation. This energy could then power devices like pacemakers, insulin pumps, and other technology inside the body. Right now, glucose-based biofuel cells are limited in lifespan and production of power, but further research could make them an ideal substitute to batteries that are currently being used inside the body. Converting glucose into electrical energy to power nanotechnology is another option that our group should consider as it is sustainable source and would be a safer alternative to lithium batteries.

Human movement is another source of energy that can be harvested to power nanotechnology. One article I found discusses the research done at Vanderbilt University to harvest energy from low-frequency human motion (as slow as 0.01 Hertz). Ultrathin layers of black phosphorous nanosheets are being used to extract energy directly from human motion. The materials developed are so thin that they can be easily incorporated into clothing. According to another article, MIT researchers found a new method to harness energy from human movements. They developed a flexible electrochemical battery that begins to bend with human motion. Pressure builds up when the battery bends and an electrical current is made. This current can then be used to power other nanodevices. As we consider how we want to harvest energy to power nanotechnologies inside the body, our group might think about the ways in which humans create energy and how this energy can be transferred for internal use.

My group plans to harness biofuels from natural materials like bacteria or human fat in order to find a way to more naturally power biotechnologies within the body. With many new nanotechnological advancements for human health, people need a way to power the technology more naturally. Batteries need replacements and may leak and cause damage within the body, while natural biofuels are a safer and more abundant source of fuel. Through our project we hope to explore the benefits of biofuels both when used in the body and in the environment. People are currently trying to reduce the harmful emissions that humans release into our atmosphere and biofuels could significantly help. Harnessing biofuels from bacteria or even human fat would significantly change the way mankind thinks about safe and renewable energy and would positively affect human health in the growing world of biotechnologies.

This review discussed alternatives to lithium-ion batteries that are used to power health devices in humans. It discussed implantable biofuel cells and how they can be used to power devices inside the human body. A glucose fuel cell (GFC) produces electrical energy from chemical energy through the oxidation of glucose and reduction of oxygen. One main challenge of implantable glucose fuel cells is that they must be able to fully interact with the human body without harming it since the cells need contact with body fluid in order to function. These cells could allow humans to convert energy within their body for the purposes of powering a medical device. Glucose biofuel cells are an option that my group can discuss in our search for alternatives to batteries used inside the body.